android: freedreno: Another build fix

android: freedreno: Another build fix

During build on Android 10, build error occurred:

'''
[ 26% 456/1718] Gen Header: libfreedreno_registers_32 <= a3xx.xml.h
FAILED: out/target/product/pinephone/gen/STATIC_LIBRARIES/libfreedreno_registers_intermediates/registers/adreno/a3xx.xml.h
/bin/bash -c "PATH=/usr/bin:\$PATH python3 external/mesa3d/src/freedreno/registers/gen_header.py external/mesa3d/src/freedreno/registers/adreno/a3xx.xml > out/target/product/pinephone/gen/STATIC_LIBRARIES/libfreedreno_registers_intermediates/registers/adreno/a3xx.xml.h"
Traceback (most recent call last):
  File "external/mesa3d/src/freedreno/registers/gen_header.py", line 470, in <module>
    main()
  File "external/mesa3d/src/freedreno/registers/gen_header.py", line 446, in main
    xml_file = sys.argv[2]
IndexError: list index out of range
'''

Align build rules with meson fixes it.

Fixes: 62ebd342 ("freedreno/registers: split header build into subdirs")
Signed-off-by: Roman Stratiienko <r.stratiienko@gmail.com>
Acked-by: Rob Clark <robdclark@gmail.com>
Acked-by: Tapani Pälli <tapani.palli@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/6170>