scummvm: bump to b5ca1b3 (2023.04.09) (#1180)

the old commit is missing due to forced push on scummvm repo

bumps to newest commit as of now to fix the following build issue,

```
builder@rz5 ~/EmuELEC (dev)> ./scripts/get scummvm
GET      scummvm (git)
    DELETE      (/home/builder/EmuELEC/sources/scummvm/scummvm-*/)
    GIT CLONE      scummvm
Cloning into '/home/builder/EmuELEC/sources/scummvm/scummvm-18add58f142f0b0fe1614f79a9a9cb48aa3eb033'...
remote: Enumerating objects: 1170225, done.
remote: Counting objects: 100% (1564/1564), done.
remote: Compressing objects: 100% (572/572), done.
remote: Total 1170225 (delta 1074), reused 1389 (delta 987), pack-reused 1168661
Receiving objects: 100% (1170225/1170225), 1.32 GiB | 14.32 MiB/s, done.
Resolving deltas: 100% (960527/960527), done.
Updating files: 100% (18388/18388), done.
There is no commit '18add58f142f0b0fe1614f79a9a9cb48aa3eb033' on branch 'master' of package 'scummvm'! Aborting!
*********** FAILED COMMAND ***********
. "${get_handler}"
**************************************
```

also cleans up package.mk and switches to new build method similar to Arch

packages/sx05re/libretro/scummvm/package.mk

@@ -19,7 +19,7 @@
 ################################################################################
 
 PKG_NAME="scummvm"
-PKG_VERSION="18add58f142f0b0fe1614f79a9a9cb48aa3eb033"
+PKG_VERSION="b5ca1b340e1a6249997fde8a60f366d039b868b4"
 PKG_ARCH="any"
 PKG_LICENSE="GPLv2"
 PKG_SITE="https://github.com/libretro/scummvm"
@@ -28,16 +28,19 @@ PKG_DEPENDS_TARGET="toolchain"
 PKG_SECTION="libretro"
 PKG_SHORTDESC="ScummVM with libretro backend."
 PKG_LONGDESC="ScummVM is a program which allows you to run certain classic graphical point-and-click adventure games, provided you already have their data files."
-PKG_TOOLCHAIN="make"
+PKG_TOOLCHAIN="manual"
 PKG_BUILD_FLAGS="-lto"
 
-pre_configure_target() {
-sed -i "s|DEFINES  += -Wno-multichar|#DEFINES  += -Wno-multichar|" Makefile.common
-PKG_MAKE_OPTS_TARGET=" all platform=rpi4_64"
+post_unpack() {
+  sed -i "s|DEFINES  += -Wno-multichar|#DEFINES  += -Wno-multichar|" ${PKG_BUILD}/Makefile.common
+}
+
+make_target() {
+  cd "${PKG_BUILD}/backends/platform/libretro"
+  make all platform=rpi4_64
 }
 
 makeinstall_target() {
   mkdir -p $INSTALL/usr/lib/libretro
-  cp scummvm_libretro.so $INSTALL/usr/lib/libretro/
-  cp scummvm_libretro.info $INSTALL/usr/lib/libretro/
+  cp "${PKG_BUILD}/backends/platform/libretro/scummvm_libretro."{so,info} $INSTALL/usr/lib/libretro/
 }