emulators/mame: fix build on powerpc*

../../../../../src/emu/video/rgbutil.cpp:365:16: error: out-of-line definition of 'bilinear_filter' does not match any declaration in 'rgbaint_t'

365 | u32 rgbaint_t::bilinear_filter(const u32 &rgb00, const u32 &rgb01, const u32 &rgb10, const u32 &rgb11, u8 u, u8 v)
    |                ^~~~~~~~~~~~~~~

In file included from ../../../../../src/emu/video/rgbutil.cpp:13:
../../../../../src/emu/video/rgbutil.h:429:29: note: type of 1st parameter of member declaration does not match definition ('u32' (aka 'unsigned int') vs 'const u32 &' (aka 'const unsigned int &'))

429 |         static u32 bilinear_filter(u32 rgb00, u32 rgb01, u32 rgb10, u32 rgb11, u8 u, u8 v) noexcept;
    |                                    ^

Archiving libpce.a...
rm -f ../../../../freebsd/bin/x64/Release/mame_mame/libpce.a
../../../../../src/emu/video/rgbutil.cpp:408:17: error: out-of-line definition of 'bilinear_filter_rgbaint' does not match any declaration in 'rgbaint_t'

408 | void rgbaint_t::bilinear_filter_rgbaint(const u32 &rgb00, const u32 &rgb01, const u32 &rgb10, const u32 &rgb11, u8 u, u8 v)
    |                 ^~~~~~~~~~~~~~~~~~~~~~~

In file included from ../../../../../src/emu/video/rgbutil.cpp:13:
../../../../../src/emu/video/rgbutil.h:430:31: note: type of 1st parameter of member declaration does not match definition ('u32' (aka 'unsigned int') vs 'const u32 &' (aka 'const unsigned int &'))

430 |         void bilinear_filter_rgbaint(u32 rgb00, u32 rgb01, u32 rgb10, u32 rgb11, u8 u, u8 v) noexcept;
    |                                      ^