*/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/include/cpu/cpu.h

@@ -9,7 +9,7 @@
 void cpu_initialize(void);
 uintptr_t cpu_get_lapic_addr(void);
 struct bus;
-int cpu_phys_address_size(void);
+unsigned int cpu_phys_address_size(void);
 
 #if ENV_RAMSTAGE
 #define __cpu_driver __attribute__((used, __section__(".rodata.cpu_driver")))