soc/intel/quark: Rename pmc.c to lpc.c

Rename the file pmc.c to lpc.c to prepare for further additions.

TEST=Build and run on Galileo Gen2

Change-Id: If98825d72878f0601f77bff8c766276dbda8a9ae
Signed-off-by: Lee Leahy <leroy.p.leahy@intel.com>
Reviewed-on: https://review.coreboot.org/14946
Tested-by: build bot (Jenkins)
Reviewed-by: Martin Roth <martinroth@google.com>

src/soc/intel/quark/Makefile.inc

@@ -27,9 +27,9 @@ ramstage-$(CONFIG_HAVE_ACPI_TABLES) += acpi.c
 ramstage-y += chip.c
 ramstage-y += ehci.c
 ramstage-y += gpio_i2c.c
+ramstage-y += lpc.c
 ramstage-y += memmap.c
 ramstage-y += northcluster.c
-ramstage-y += pmc.c
 ramstage-y += reg_access.c
 ramstage-y += tsc_freq.c
 ramstage-$(CONFIG_ENABLE_BUILTIN_HSUART1) += uart_common.c