arm64: proton-pack: Add new CPUs 'k' values for branch mitigation

Update the list of 'k' values for the branch mitigation from arm's
website.

Add the values for Cortex-X1C. The MIDR_EL1 value can be found here:
https://developer.arm.com/documentation/101968/0002/Register-descriptions/AArch>

Link: https://developer.arm.com/documentation/110280/2-0/?lang=en
Signed-off-by: James Morse <james.morse@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>

Author: James Morse

arch/arm64/include/asm/cputype.h

@@ -81,6 +81,7 @@
 #define ARM_CPU_PART_CORTEX_A78AE	0xD42
 #define ARM_CPU_PART_CORTEX_X1		0xD44
 #define ARM_CPU_PART_CORTEX_A510	0xD46
+#define ARM_CPU_PART_CORTEX_X1C		0xD4C
 #define ARM_CPU_PART_CORTEX_A520	0xD80
 #define ARM_CPU_PART_CORTEX_A710	0xD47
 #define ARM_CPU_PART_CORTEX_A715	0xD4D
@@ -168,6 +169,7 @@
 #define MIDR_CORTEX_A78AE	MIDR_CPU_MODEL(ARM_CPU_IMP_ARM, ARM_CPU_PART_CORTEX_A78AE)
 #define MIDR_CORTEX_X1	MIDR_CPU_MODEL(ARM_CPU_IMP_ARM, ARM_CPU_PART_CORTEX_X1)
 #define MIDR_CORTEX_A510 MIDR_CPU_MODEL(ARM_CPU_IMP_ARM, ARM_CPU_PART_CORTEX_A510)
+#define MIDR_CORTEX_X1C MIDR_CPU_MODEL(ARM_CPU_IMP_ARM, ARM_CPU_PART_CORTEX_X1C)
 #define MIDR_CORTEX_A520 MIDR_CPU_MODEL(ARM_CPU_IMP_ARM, ARM_CPU_PART_CORTEX_A520)
 #define MIDR_CORTEX_A710 MIDR_CPU_MODEL(ARM_CPU_IMP_ARM, ARM_CPU_PART_CORTEX_A710)
 #define MIDR_CORTEX_A715 MIDR_CPU_MODEL(ARM_CPU_IMP_ARM, ARM_CPU_PART_CORTEX_A715)

arch/arm64/kernel/proton-pack.c

@@ -891,6 +891,7 @@ static u8 spectre_bhb_loop_affected(void)
 		MIDR_ALL_VERSIONS(MIDR_CORTEX_A78AE),
 		MIDR_ALL_VERSIONS(MIDR_CORTEX_A78C),
 		MIDR_ALL_VERSIONS(MIDR_CORTEX_X1),
+		MIDR_ALL_VERSIONS(MIDR_CORTEX_X1C),
 		MIDR_ALL_VERSIONS(MIDR_CORTEX_A710),
 		MIDR_ALL_VERSIONS(MIDR_CORTEX_X2),
 		MIDR_ALL_VERSIONS(MIDR_NEOVERSE_N2),