payloads/ipxe/kconfig: Fix option name prefix
With commit
238ff1e9c7 ("payloads/ipxe: Prefix iPXE options with "IPXE"
instead "PXE""), the prefix for iPXE related Kconfig identifiers was
unified to "IPXE". So rename the identifier for the TRUST_CMD option as
well, which was introduced later.
Change-Id: I918358b859003503526ba7849494bb23f8c893fd
Signed-off-by: Felix Singer <felixsinger@posteo.net>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/83361
Reviewed-by: Nicholas Chin <nic.c3.14@gmail.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>