Remove amd64_ platform prefix

kernel/amd64/msr.c

@@ -2,14 +2,14 @@
 #include <libk/std.h>
 
 /// Read a model-specific register
-uint64_t amd64_rdmsr (uint32_t msr) {
+uint64_t rdmsr (uint32_t msr) {
   uint32_t low, high;
   __asm__ volatile ("rdmsr" : "=a"(low), "=d"(high) : "c"(msr));
   return ((uint64_t)high << 32 | (uint64_t)low);
 }
 
 /// Write a model-specific register
-void amd64_wrmsr (uint32_t msr, uint64_t value) {
+void wrmsr (uint32_t msr, uint64_t value) {
   uint32_t low = (uint32_t)(value & 0xFFFFFFFF);
   uint32_t high = (uint32_t)(value >> 32);
   __asm__ volatile ("wrmsr" ::"c"(msr), "a"(low), "d"(high));