*/include/cpu: use unsigned int for number of address bits

The number of physical address bits and reserved address bits shouldn't
ever be negative, so change the return type of cpu_phys_address_size,
get_reserved_phys_addr_bits, and get_tme_keyid_bits from int to unsigned
int.

Signed-off-by: Felix Held <felix-coreboot@felixheld.de>
Change-Id: I9e67db6bf0c38f743b50e7273449cc028de13a8c
Reviewed-on: https://review.coreboot.org/c/coreboot/+/78072
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Marshall Dawson <marshalldawson3rd@gmail.com>
Reviewed-by: Matt DeVillier <matt.devillier@amd.corp-partner.google.com>
Reviewed-by: Varshit Pandya <pandyavarshit@gmail.com>

src/arch/x86/cpu_common.c

@@ -44,7 +44,7 @@ unsigned int cpu_cpuid_extended_level(void)
 	return cpuid_eax(0x80000000);
 }
 
-int cpu_phys_address_size(void)
+unsigned int cpu_phys_address_size(void)
 {
 	if (!(cpu_have_cpuid()))
 		return 32;