arm: k3: select tifsstub via board_fit_config_name_match

arm: k3: select tifsstub via board_fit_config_name_match

TI K3 AM62x/AM62Ax/AM62Px boards carry two or three mutually-exclusive
tifsstub variants in their tispl.bin FIT images, all at the same load
address. The existing approach loads every variant and then discards
the wrong ones at runtime via a *p_size = 0 hack in
board_fit_image_post_process(). Switch to selecting the appropriate
FIT configuration up front via board_fit_config_name_match() so only
the correct tifsstub is loaded in the first place.

board_fit_config_name_match() is invoked by the R5 SPL during FIT
config selection. get_device_type() is a simple register read that is
available at that point, so the security state can be determined
early. The matching logic is factored into
k3_fit_config_match_security_state() in arch/arm/mach-k3/common.c so
it can be shared by any K3 board that wants this scheme. It matches
configurations by a suffix appended to the description string:

  -hs-se  ->  HS-SE  (K3_DEVICE_TYPE_HS_SE)
  -hs-fs  ->  HS-FS  (K3_DEVICE_TYPE_HS_FS)
  -gp     ->  GP     (K3_DEVICE_TYPE_GP)

Configurations without a security-state suffix (e.g. u-boot.img) do
not match and fall through to the DTS-specified default config
naturally.

Each TI EVM board defines its board_fit_config_name_match() as a thin
wrapper around the shared helper:
- board/ti/am62x/evm.c   (AM625 SK: hs-se, hs-fs, gp)
- board/ti/am62ax/evm.c  (AM62A SK: hs-se, hs-fs, gp)
- board/ti/am62px/evm.c  (AM62P SK: hs-se, hs-fs, gp)

FIT configurations are split per security state in:
- arch/arm/dts/k3-am625-sk-binman.dtsi
  (ti-falcon, ti-spl, ti-spl_unsigned: conf-hs-se/conf-hs-fs/conf-gp)
- arch/arm/dts/k3-am62a-sk-binman.dtsi
  (ti-falcon, ti-spl: conf-hs-se/conf-hs-fs; no GP variant on AM62A)
- arch/arm/dts/k3-am62p-sk-binman.dtsi
  (ti-falcon, ti-spl: conf-hs-se/conf-hs-fs; no GP variant on AM62P)

The runtime filter in board_fit_image_post_process() is intentionally
left in place. It becomes redundant once every board using the AM62x
family dtsi files migrates to per-state configurations. The dtsi for
phytec phycore and toradex verdin boards is updated by separate
patches in this series, and the now-redundant runtime filter is
removed by the final patch in the series.

Signed-off-by: Aristo Chen <aristo.chen@canonical.com>
Reviewed-by: Anshul Dalal <anshuld@ti.com>