ArmPlatformPkg: PEIM startup is not an error

ArmPlatformPkg: PEIM startup is not an error

"MemoryInitPeim.c" and "PlatformPeim.c" log startup messages on the
EFI_D_ERROR level. This clutters a strictly EFI_D_ERROR level log
needlessly; change the log bitmask of these messages to EFI_D_LOAD |
EFI_D_INFO.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Leif Lindholm <leif.lindholm@arm.com>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@16984 6f19259b-4bc3-4df7-8a09-765794883524