Use @DIRNAME@ in Metrowerks cross files to point to linker script

cross/metrowerks-arm.txt

@@ -2,12 +2,6 @@
 # toolchain is added to the environment(PATH) variable, so that
 # Meson can find the binaries while building.
 
-# You should also do one of the following to ensure Meson can
-# locate the .lcf linker script:
-# - Add the cross directory to PATH as well
-# - Edit c_link_args and cpp_link_args with the full
-#   path to the .lcf file on your machine
-
 [binaries]
 c = 'mwccarm'
 c_ld = 'mwldarm'
@@ -18,11 +12,12 @@ as = 'mwasmarm'
 
 [built-in options]
 c_args = ['-lang', 'c99', '-D_NITRO', '-nosyspath']
-c_link_args = 'metrowerks.lcf'
+c_link_args = '@DIRNAME@' / 'metrowerks.lcf'
 cpp_args = ['-lang', 'c++', '-D_NITRO', '-nosyspath']
-cpp_link_args = 'metrowerks.lcf'
+cpp_link_args = '@DIRNAME@' / 'metrowerks.lcf'
 
 [host_machine]
 system = 'bare metal'
+cpu = 'arm'
 cpu_family = 'arm'
-endian = 'little'
+endian = 'little'

cross/metrowerks-eppc.txt

@@ -2,12 +2,6 @@
 # of choice is added to the environment(PATH) variable, so that
 # Meson can find the binaries while building.
 
-# You should also do one of the following to ensure Meson can
-# locate the .lcf linker script:
-# - Add the cross directory to PATH as well
-# - Edit c_link_args and cpp_link_args with the full
-#   path to the lcf file on your machine
-
 [binaries]
 c = 'mwcceppc'
 c_ld = 'mwldeppc'
@@ -18,11 +12,12 @@ as = 'mwasmeppc'
 
 [built-in options]
 c_args = ['-lang', 'c99', '-nosyspath']
-c_link_args = 'metrowerks.lcf'
+c_link_args = '@DIRNAME@' / 'metrowerks.lcf'
 cpp_args = ['-lang', 'c++', '-nosyspath']
-cpp_link_args = 'metrowerks.lcf'
+cpp_link_args = '@DIRNAME@' / 'metrowerks.lcf'
 
 [host_machine]
 system = 'bare metal'
+cpu = 'ppc'
 cpu_family = 'ppc'
-endian = 'little'
+endian = 'little'