soc/intel: rename get_prmrr_size

get_prmrr_size does not return the actual PRMRR size but a valid PRMRR
size with repect to the users choice in Kconfig. Thus, rename it from
`get_prmrr_size` to `get_valid_prmrr_size` to avoid confusion about what
it does.

Also fix the broken comment in cpulib.h.

Change-Id: Id243be50acb741f2c3118ddde082743d08983a53
Signed-off-by: Michael Niewöhner <foss@mniewoehner.de>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/45414
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Nico Huber <nico.h@gmx.de>

src/soc/intel/tigerlake/romstage/fsp_params.c

@@ -63,7 +63,7 @@ static void soc_memory_init_params(FSP_M_CONFIG *m_cfg,
 	memcpy(m_cfg->PcieClkSrcClkReq, config->PcieClkSrcClkReq,
 		sizeof(config->PcieClkSrcClkReq));
 
-	m_cfg->PrmrrSize = get_prmrr_size();
+	m_cfg->PrmrrSize = get_valid_prmrr_size();
 	m_cfg->EnableC6Dram = config->enable_c6dram;
 	/* Disable BIOS Guard */
 	m_cfg->BiosGuard = 0;