build-sys: correct ARM32 GNU EFI boot binary build

build-sys: correct ARM32 GNU EFI boot binary build

Due to ARM not having an EFI capable objcopy we need to use the binary
output argument. This is correctly set up for AArch64 but is missed
when building for ARM32. This patch adds the ARCH_ARM automake define
which can then be used in the makefile to determine if to use the
correct linker flags.

The addition of the ARM32 flags is a copy and paste from the AArch64 to
create a logical OR for the ARCH_AARCH64 and ARCH_ARM variables. I
couldn't figure out a better way to create the conditional with basic
Make language constructs.