bitops.h: revert db1ffc3 ("qemu/bitops.h: add bitrev8 implementation")

Commit db1ffc3 ("qemu/bitops.h: add bitrev8 implementation") introduced
a bitrev8() function to reverse the bit ordering required for storing the
MAC address in the q800 PROM.

This function is not required since QEMU implements its own revbit8()
function which does exactly the same thing. Remove the extraneous
bitrev8() function and switch its only caller in hw/m68k/q800.c to
use revbit8() instead.

Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20210725110557.3007-1-mark.cave-ayland@ilande.co.uk>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

hw/m68k/q800.c

@@ -334,7 +334,7 @@ static void q800_init(MachineState *machine)
     prom = memory_region_get_ram_ptr(dp8393x_prom);
     checksum = 0;
     for (i = 0; i < 6; i++) {
-        prom[i] = bitrev8(nd_table[0].macaddr.a[i]);
+        prom[i] = revbit8(nd_table[0].macaddr.a[i]);
         checksum ^= prom[i];
     }
     prom[7] = 0xff - checksum;

include/qemu/bitops.h

@@ -618,26 +618,4 @@ static inline uint64_t half_unshuffle64(uint64_t x)
     return x;
 }
 
-/**
- * bitrev8:
- * @x: 8-bit value to be reversed
- *
- * Given an input value with bits::
- *
- *   ABCDEFGH
- *
- * return the value with its bits reversed from left to right::
- *
- *   HGFEDCBA
- *
- * Returns: the bit-reversed value.
- */
-static inline uint8_t bitrev8(uint8_t x)
-{
-    x = ((x >> 1) & 0x55) | ((x << 1) & 0xaa);
-    x = ((x >> 2) & 0x33) | ((x << 2) & 0xcc);
-    x = (x >> 4) | (x << 4) ;
-    return x;
-}
-
 #endif