amd_spi100: Use source-aligned read for the FIFO

Makes reading twice as fast (on this Raven Ridge).

Change-Id: I878c7603e514859c48a9c7823f98a391ea921b21
Signed-off-by: Nico Huber <nico.h@gmx.de>
Reviewed-on: https://review.coreboot.org/c/flashrom-stable/+/72582
Reviewed-by: Arthur Heymans <arthur@aheymans.xyz>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
diff --git a/amd_spi100.c b/amd_spi100.c
index f8af0de..39b293f 100644
--- a/amd_spi100.c
+++ b/amd_spi100.c
@@ -61,7 +61,7 @@
 
 static void spi100_readn(const struct spi100 *spi100, unsigned int reg, uint8_t *data, size_t len)
 {
-	mmio_readn(spi100->spibar + reg, data, len);
+	mmio_readn_aligned(spi100->spibar + reg, data, len, 4);
 }
 
 static int spi100_check_readwritecnt(const unsigned int writecnt, const unsigned int readcnt)