fix ROT_IRQ regressions from #1696

[hawkw]

This branch fixes a pair of regressions I introduced in PR #1696 :

• sprot: fix backwards ROT_IRQ edge detection (8be5f3c)

  In PR sprot: turn ROT_IRQ into a real IRQ #1696, I broke the drv-stm32h7-sprot-server code for waiting for
  ROT_IRQ to change state. The ROT_IRQ signal is active low (and in
  the schematic it's called ROT_TO_SP_IRQ_L), but in the code, the pin
  is just referred to as ROT_IRQ, so I configured edge sensitivity
  backwards, meaning we missed the IRQ signal. Oops, my bad.

  This commit changes the edge sensitivity to wait for the falling edge
  when waiting for ROT_IRQ to be asserted, and to wait for the rising
  edge when waiting for it to be deasserted, instead of the other way
  around. Now, it actually works correctly.

  eliza@lurch ~ $ pfexec humility -t psc-sp flash && faux-mgs --interface axf1 --discovery-addr [fe80::aa40:25ff:fe06:103%3]:11111 state
  humility: attaching with chip set to "STM32H753ZITx"
  humility: attached to 0483:374e:0037001B5553500720393256 via ST-Link V3
  humility: flash/archive mismatch; reflashing
  humility: flashing done
  Apr 07 18:07:31.725 INFO creating SP handle on interface axf1, component: faux-mgs
  Apr 07 18:07:33.727 INFO initial discovery complete, addr: [fe80::aa40:25ff:fe06:103%3]:11111, interface: axf1, component: faux-mgs
  Apr 07 18:07:33.733 INFO V2(SpStateV2 { hubris_archive_id: [53, 140, 208, 151, 27, 45, 232, 176], serial_number: [66, 82, 77, 52, 53, 50, 50, 48, 48, 48, 51, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0], model: [57, 49, 51, 45, 48, 48, 48, 48, 48, 48, 51, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0], revision: 8, base_mac_address: [168, 64, 37, 6, 1, 2], power_state: A2, rot: Ok(RotStateV2 { active: A, persistent_boot_preference: A, pending_persistent_boot_preference: None, transient_boot_preference: None, slot_a_sha3_256_digest: Some([175, 36, 236, 22, 163, 153, 65, 80, 159, 252, 36, 30, 77, 25, 52, 93, 158, 50, 246, 178, 139, 62, 218, 107, 9, 29, 129, 29, 100, 174, 133, 25]), slot_b_sha3_256_digest: Some([139, 130, 30, 66, 20, 39, 59, 105, 242, 21, 10, 7, 147, 124, 64, 253, 57, 156, 212, 176, 189, 255, 59, 243, 172, 9, 204, 75, 221, 250, 208, 53]) }) }), component: faux-mgs
  hubris archive: 358cd0971b2de8b0
  serial number: BRM45220003
  model: 913-0000003
  revision: 8
  base MAC address: a8:40:25:06:01:02
  power state: A2
  RotStateV2 {
   active: A,
   persistent_boot_preference: A,
   pending_persistent_boot_preference: None,
   transient_boot_preference: None
   slot_a_sha3_256_digest: af24ec16a39941509ffc241e4d19345d9e32f6b28b3eda6b091d811d64ae8519,
   slot_b_sha3_256_digest: 8b821e4214273b69f2150a07937c40fd399cd4b0bdff3bf3ac09cc4bddfad035,
  }
  eliza@lurch ~ $ pfexec humility -t psc-sp ringbuf sprot_server
  humility: attached to 0483:374e:0037001B5553500720393256 via ST-Link V3
  humility: ring buffer drv_stm32h7_sprot_server::__RINGBUF in sprot:
   NDX LINE      GEN    COUNT PAYLOAD
     0  243        1        1 Sent(0xa)
     1  365        1        1 WaitRotIrq(true, 0x5)
     2  285        1        1 Received(0x51)
  eliza@lurch ~ $

• psc: fix wrong ROT_IRQ pin (5046b54)

  Whoops, I accidentally copied the configuration from Gimletlet rather
  than from Gimlet/Sidecar, so this is wrong.

[lzrd]

tested on my gimletlet/rot-carrier