mfd: omap-usb-host: Remove some unused functions

Removes some functions that are not used anywhere:
usbhs_readb() usbhs_writeb()

This was partially found by using a static code analysis program called cppcheck.
Signed-off-by: NRickard Strandqvist <rickard_strandqvist@spectrumdigital.se>
Signed-off-by: NLee Jones <lee.jones@linaro.org>

drivers/mfd/omap-usb-host.c

@@ -129,16 +129,6 @@ static inline u32 usbhs_read(void __iomem *base, u32 reg)
 	return readl_relaxed(base + reg);
 }
 
-static inline void usbhs_writeb(void __iomem *base, u8 reg, u8 val)
-{
-	writeb_relaxed(val, base + reg);
-}
-
-static inline u8 usbhs_readb(void __iomem *base, u8 reg)
-{
-	return readb_relaxed(base + reg);
-}
-
 /*-------------------------------------------------------------------------*/
 
 /**