pinctrl: qcom: Add EGPIO feature support to pinctrl driver

Island IO can be assigned to Apps TLMM dynamically
if that island is not using the pin for any connectivity.
Add support for enabling EGPIO feature if the pin can
support it. EGPIO_PRESENT bit shows if EGPIO feature
is present or not for particular pin. Once EGPIO_ENABLE
bit is set the pin is now controlled by Apps TLMM.
When pinctrl properties are getting initialized by device
driver framework, pin functions select would call to
msm_pinmux_set_mux function to select pin function and
enable EGPIO.

Change-Id: I64514904096286f2a5df351880cd56d753f0658f
Signed-off-by: Prasad Sodagudi <psodagud@codeaurora.org>